Ceramic composites (2Ni0.41Zn0.41Cu 0.18Fe2O4-BaTiO3) were successfully prepared by a direct solid-state reaction of raw materials (BaCO3, CuO, α-Fe2O3, NiO, TiO2, and ZnO). X-ray diffraction (XRD) and electron probe micro analysis (EPMA) measurements were performed for these samples and it is confirmed that the composites consist of spinel ferrite and BaTiO3 phases. The composites are so homogeneous that the ferrite and BaTiO3 grains do not react with each other and have radii in the range of 1-5 μm. Hexagonal BaTiO3 (h-BaTiO 3) can be made in this composite form with a sintering temperature of 1200°C, although h-BaTiO3 can be usually synthesized above 1460°C. The freezing-point depression of BaTiO3 takes place due to the mixing with the spinel ferrite, which may result in the formation of h-BaTiO3 at a low temperature of 1200°C.
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